This invention relates to the treatment of tumors within an organism, and more specifically, to encapsulating, destroying and removing malignant tumors from an organism.
Death from cancer most often occurs from metastases which become apparent years after the attempted curative surgery. Tragically, the very acts of biopsy and surgical excision disseminate tumor cells into the systemic circulation and into the regional lymphatics. Improvement in long term cancer survival is dependent on answering two questions: (1) How can we accurately diagnose cancer without shedding tumor cells? (2) How can we surgically remove tumors without shedding tumor cells, and without stimulating any residual tumor cells?
New possibilities for concentrating rare circulating tumor cells from the peripheral blood and possibilities for detection of rare tumor cells in marrow may allow adequate certainty to proceed with lumpectomy as biopsy, avoiding one tumor shedding exposure. If clinical presentation and diagnostic images are shown to be more than 90 percent predictive in defined circumstances, biopsy may also be bypassed with adequate informed consent. In cases where biopsy cannot be eliminated, strategies for minimizing tumor shedding should be evaluated. Broadly, both physical and chemical methods are possible.
Physical methods include blockade of lymphatics using injection of substances around the full three dimensional perimeter of the tumor (peritumoral injection) in order to clog or constrict the lumphatics. Peritumoral injection of the patient""s fresh whole blood which has been freshly hemolyzed by addition of sterile water for injection is a physiologically attractive maneuver. Not only are the lymphatics obstructed by red cells, but tissue clotting mechanisms are activated and small veins may clot. Edema should further close off lumphatics and small veins. Local macrophage activation may result in destruction of some tumor cells.
Peritumoral blockade is probably not adequate by itself to eliminate tumor shedding in cases where the tumor itself is surgically entered, rather than only pierced by a biopsy needle. If we want to excise small tumors with minimal invasion, we need a truly robust way to contain and kill spilled tumor cells.
Primary and metastatic malignant tumors can be treated by a variety of methods, including surgical excision, chemotherapy and radiation therapy. A primary goal of all of these therapeutic methods is to remove and/or inactivate the tumor while causing as little collateral damage as possible to healthy tissues within the organism being treated.
Surgical excision of a tumor with a minimum of collateral damage to healthy tissues has been facilitated by advances in the arts of microsurgery, endoscopic surgery and real-time imaging. In particular, surgical techniques using surgical/imaging devices enable surgeons to precisely distinguish in real-time between tissues to be removed and tissues to be preserved intact within an organism. Unfortunately, it has been found that the very act of surgically excising a tumor from an organism, no matter how precise the surgical technique, can cause the tumor to metastasize, thus causing collateral damage to healthy tissues which may not become clinically apparent for months or years, but which will almost always progress to kill the patient.
Although advances in chemotherapy also promise to minimize collateral damage, researchers still seek a xe2x80x9cmagic bulletxe2x80x9d which would effectively target only malignant tissues for destruction, without damaging healthy tissues.
In the meantime, it has been proposed to surround the tumor with a barrier which would protect surrounding healthy tissues from the damaging effects of locally injected chemotherapy. See, e.g., U.S. Pat. No. 5,458,597.
U.S. Pat. No. 5,458,597 deals with creation of a diffusion barrier of heat coagulated tissue proteins in order to restrict the outflow of locally injected chemotherapeutic agents from the thermally created tumor crater. Necrotic tissues and the coagulation capsule are left behind, where they are at substantial risk of becoming infected.
U.S. Pat. No. 5,472,441 teaches providing a radio-frequency induced tissue coagulation barrier around a tumor to contain locally injected chemotherapy. Only metastatic cancers with no prospect for cure would be suitable for such a palliative nonsurgical approach where the additional risk of shedding tumor cells by piercing the tumor is irrelevant because of the short lifespan of patients with metastatic disease. Failure to remove the killed tissues as taught in this patent places the patient at risk for infection.
Collateral damage to normal tissues adjacent to cancerous tumors also limits the effectiveness of radiation therapy. Radiation sensitizers have been sought to selectively increase damage to malignant tissues while sparing healthy tissues. Unfortunately, these radiation sensitizers can themselves be toxic to healthy tissues when injected at levels high enough to achieve their radiation enhancing effect, and/or might not persist in the area of the tumor for a time sufficient to enhance the effect of radiation on the tumor.
Thus, there is a still unsatisfied need for tumor therapies that are effective in removing and/or inactivating the tumor without causing significant collateral damage to healthy tissues, and without causing microscopic shedding of tumor cells which create diagnosable metastases months or years later.
All references cited herein are incorporated herein by reference in their entireties.
The instant invention addresses at least the foregoing deficiencies of the prior art by providing methods for conducting an operation on a living organism, said method comprising:
providing a channel around a tissue of said organism; and
infusing into said channel an encapsulating composition
to encapsulate said tissue in a capsule,
wherein said capsule impedes materials encapsulated therein from migrating to other tissue outside said capsule.
Also provided are apparatuses for performing methods of the invention.
The invention also provides an improved method of radiation therapy comprising administering a radiation enhancing agent in or near a tissue to be treated. The radiation therapy method can conducted with or without encapsulation.